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module clcdrag_m |
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IMPLICIT NONE |
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|
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contains |
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SUBROUTINE clcdrag(nsrf, speed, t, q, zgeop, ts, qsurf, rugos, pcfm, pcfh) |
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! From LMDZ4/libf/phylmd/clcdrag.F90, version 1.1.1.1, 2004/05/19 12:53:07 |
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|
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! Objet : calcul des cdrags pour le moment (pcfm) et les flux de |
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! chaleur sensible et latente (pcfh). |
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! Calculer le frottement au sol (drag coefficient) |
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|
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USE indicesol, ONLY: is_oce |
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use nr_util, only: assert_eq |
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USE suphec_m, ONLY: rcpd, retv, rg |
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USE yoethf_m, ONLY: rvtmp2 |
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|
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INTEGER, intent(in):: nsrf ! indice pour le type de surface |
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|
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REAL, intent(in):: speed(:) ! (knon) |
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! norm of the wind at the first model layer |
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|
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REAL, intent(in):: t(:) ! (knon) |
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! temperature de l'air au 1er niveau du modele |
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|
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REAL, intent(in):: q(:) ! (knon) ! humidite de l'air au 1er niveau du modele |
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REAL, intent(in):: zgeop(:) ! (knon) géopotentiel au 1er niveau du modèle |
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REAL, intent(in):: ts(:) ! (knon) temperature de l'air a la surface |
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REAL, intent(in):: qsurf(:) ! (knon) humidite de l'air a la surface |
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REAL, intent(in):: rugos(:) ! (knon) rugosit\'e |
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REAL, intent(out):: pcfm(:) ! (knon) drag coefficient pour le moment |
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|
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REAL, intent(out):: pcfh(:) ! (knon) |
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! drag coefficient pour les flux de chaleur latente et sensible |
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|
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! Local: |
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|
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! Quelques constantes et options: |
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REAL, PARAMETER:: ckap=0.40, cb=5.0, cc=5.0, cd=5.0, cepdu2=0.1**2 |
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|
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INTEGER:: i, knon |
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REAL:: zdu2, ztsolv, ztvd, zscf |
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REAL:: zucf, zcr |
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REAL:: friv, frih |
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REAL, dimension(size(speed)):: zcfm1, zcfm2 |
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REAL, dimension(size(speed)):: zcfh1, zcfh2 |
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REAL, dimension(size(speed)):: zcdn |
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REAL, dimension(size(speed)):: zri |
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|
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!-------------------------------------------------------------------- |
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|
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knon = assert_eq([size(speed), size(t), size(q), size(zgeop), size(ts), & |
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size(qsurf), size(rugos), size(pcfm), size(pcfh), size(pcfm)], & |
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"clcdrag knon") |
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|
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DO i = 1, knon |
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zdu2 = max(cepdu2,speed(i)**2) |
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ztsolv = ts(i) * (1.0+RETV*qsurf(i)) |
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ztvd = (t(i)+zgeop(i)/RCPD/(1.+RVTMP2*q(i))) & |
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*(1.+RETV*q(i)) |
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zri(i) = zgeop(i)*(ztvd-ztsolv)/(zdu2*ztvd) |
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zcdn(i) = (ckap/log(1.+zgeop(i)/(RG*rugos(i))))**2 |
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|
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IF (zri(i) .gt. 0.) THEN |
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! situation stable |
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zri(i) = min(20.,zri(i)) |
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zscf = SQRT(1.+cd*ABS(zri(i))) |
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FRIV = AMAX1(1. / (1.+2.*CB*zri(i)/ZSCF), 0.1) |
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zcfm1(i) = zcdn(i) * FRIV |
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FRIH = AMAX1(1./ (1.+3.*CB*zri(i)*ZSCF), 0.1 ) |
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zcfh1(i) = 0.8 * zcdn(i) * FRIH |
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pcfm(i) = zcfm1(i) |
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pcfh(i) = zcfh1(i) |
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ELSE |
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! situation instable |
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zucf = 1./(1.+3.0*cb*cc*zcdn(i)*SQRT(ABS(zri(i)) & |
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*(1.0+zgeop(i)/(RG*rugos(i))))) |
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zcfm2(i) = zcdn(i)*amax1((1.-2.0*cb*zri(i)*zucf),0.1) |
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zcfh2(i) = 0.8 * zcdn(i)*amax1((1.-3.0*cb*zri(i)*zucf),0.1) |
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pcfm(i) = zcfm2(i) |
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pcfh(i) = zcfh2(i) |
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zcr = (0.0016/(zcdn(i)*SQRT(zdu2)))*ABS(ztvd-ztsolv)**(1./3.) |
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IF(nsrf == is_oce) pcfh(i) = 0.8 * zcdn(i) & |
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* (1. + zcr**1.25)**(1. / 1.25) |
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ENDIF |
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END DO |
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|
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END SUBROUTINE clcdrag |
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|
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end module clcdrag_m |